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Litter decomposition is an important soil nutrient source that promotes vegetation in deteriorated riparian zones worldwide. The periodic submergence and sediment burial effects on two prominent annual herbaceous plants (Echinochloa crusgali and Bidens tripartite) are little known in mega-reservoir settings. Our study focuses on the mass and carbon loss and nutrient release from E. crusgali and B. tripartitle litter and changes in soil properties, which are important for riparian zone rehabilitation in the Three Gorges Dam Reservoir, China. This study adopted the litter bag method to explore the nutrient change characteristics and changes in soil properties at different sediment burial depths under flooding scenarios. Three burial depths (0 cm, 5 cm, and 10 cm) were used for these two plants, and the experiment lasted for 180 days. The results revealed that the litter decay rate was high at first in the incubation experiment, and the nutrient loss rate followed the pattern of K &gt, P &gt, N &gt, C. The relationship between % C remaining and % mass remaining was nearly 1:1, and the total amount of P exhibited a leaching–enrichment–release state in the decomposition process. Nutrients were changed significantly in the soil and overlying water at the first decomposition stage. Still, the total soil nutrient change was insignificant at the end, except for the 10 cm burial of B. tripartitle. Moreover, oxidation–reduction potential was the main factor in the litter decomposition process at different burial depths. This study indicated that sediment deposition reduced litter mass loss, slowed down the release of N and P, and retained more C, but promoted the release of K. Conclusively, in litter decomposition under waterlogging, the total soil nutrient content changed little. However, litter does more to the soil than that. Therefore, it is necessary to study the residual soil litter’s continuous output after the water level declines for restoration purposes.

The vast number of chemicals potentially reaching aquatic environment pose a challenge in maintaining the quality of water resources. However, best management practices to improve water quality are typically focused on reducing nutrient transport without assessing how these practices may impact the occurrence of micropollutants. The potential for co-management of nutrients and organic micropollutants exists, but few studies have comprehensively evaluated the suite of contaminants associated with different water quality management practices (riparian zone restoration, stormwater management, etc.). Furthermore, most studies dealing with the determination of micropollutants in environmental samples include only a limited number of target analytes, leaving many contaminants undetected. To address this limitation, there has been a gradual shift in environmental monitoring from using target analysis to either suspect screening analysis (SSA) or non-targeted analysis (NTA), which relies on accurate mass measurements, mass spectral fragmentation patterns, and retention time information obtained using liquid chromatography coupled to high-resolution mass spectrometry. The work presented in this paper focuses on a wide-scope detection of micropollutants in surface water samples from the Potomac River watershed (United States). An in-house database composed of 1039 compounds based on experimental analysis of primary standards was established, and SSA workflow was optimized and applied to determine the presence of micropollutants in surface water. A total of 103 micropollutants were detected in the samples, some of which are contaminants that were not previously monitored and belong to various classes such as pharmaceuticals, personal care products, per-and polyfluoroalkyl substances and other persistent industrial chemicals. The impact of best management practices being implemented for nitrogen and phosphorus reductions were also assessed for their potential to reduce micropollutant transport. This work illustrates the advantages of suspect screening methods to determine a large number of micropollutants in environmental samples and reveals the potential to co-manage a diverse array of micropollutants based on shared transport and transformation mechanisms in watersheds., Highlights • In-house suspect screening database that include 1039 micropollutants was developed • Suspect screening analysis (SSA) workflow was optimized to increase chemical coverage • SSA detected 103 micropollutants in the samples collected from Potomac watershed • BMPs result in co-management of nutrients and micropollutants transport

Background Globally, vegetation in riparian zones is frequently the target of restoration efforts because of its importance in reducing the input of eroded sediment and agricultural nutrient runoff to surface waters. Here we examine the potential of riparian zone restoration to enhance carbon sequestration. We measured soil and woody biomass carbon stocks, as well as soil carbon properties, in a long-term chronosequence of 42 streambank revegetation projects in northern California rangelands, varying in restoration age from 1 to 45 years old. Results Where revegetation was successful, we found that soil carbon measured to 50 cm depth increased at a rate of 0.87 Mg C ha−1 year−1 on the floodplain and 1.12 Mg C ha−1 year−1 on the upper bank landform. Restored sites also exhibited trends toward increased soil carbon permanence, including an increased C:N ratio and lower fulvic acid: humic acid ratio. Tree and shrub carbon in restored sites was modeled to achieve a 50-year maximum of 187.5 Mg C ha−1 in the channel, 279.3 Mg ha−1 in the floodplain, and 238.66 Mg ha−1 on the upper bank. After 20 years of restoration, the value of this carbon at current per-ton C prices would amount to $US 15,000 per km of restored stream. Conclusion We conclude that revegetating rangeland streambanks for erosion control has a substantial additional benefit of mitigating global climate change, and should be considered in carbon accounting and any associated financial compensation mechanisms.

A lowland stream was subject to an ecological restoration with the creation of a 11 m wide buffer strip reconnected to the river channel. Monitoring results revealed the efficiency of this buffer system in removing nitrogen. This site was compared with other buffer strips designed according to the technical specifications of Italian Standard 5.2 in Italy (M.D. 27417, December 22, 2011). While some of the systems resulted very effective in inorganic nitrogen removal, reaching values of 62 and 75%, two of the monitored sites resulted completely ineffective even if realized according to the required technical specifications. Our results indicate that this was due to a lack of hydraulic connectivity with Corg-rich active soil layers in contact with the rhizosphere. A comparison of the main factors limiting nitrogen retention is proposed, highlighting the key role played by hydrology and in particular by groundwater depth and soil carbon availability. One of the most common objections to the prescriptions of Cross-compliance standard 5.2, concerning the excessive narrowness of buffer strips (5 m), did not seem to be particularly relevant. Starting from the comparison of monitoring results obtained at different experimental sites, this contribution provides practical indications about the correct planning and management of buffer strips for nitrogen retention.

International audience; Riparian zones have disproportional ecological importance relative to their size. For decades, the functionality of riparian zones has been altered, with detrimental consequences on biodiversity. Recently, riparian zone restoration has become a major issue. When channel mobility cannot be restored and when erosion control is of primary concern, soil bioengineering techniques are often viewed as a compromise solution. We studied 37 riverbanks, from civil engineering to soil bioengineering, plus natural willow stands, in the foothills of the Alps and Jura Mountains. Using a principal component analysis, we first studied whether terrestrial and aquatic habitat variables varied among riverbank stabilization structures and bank stabilization age and built a synthetic index of riparian habitat quality reflecting the multivariate similarity of riverbank sites. Then, using a modelling approach, we tested whether multi-taxonomic diversity responded to changes in habitat quality and to broadscale environmental variables (i.e., climate, hydrology and land cover). Soil bioengineering techniques, especially willow fascines and to lower extend vegetated crib wall, enhanced riparian habitat quality by allowing for a greater richness and density of pioneer tree species but also for a larger cover of high quality aquatic micro-habitats. This increase in riparian habitat quality induced an increase in both terrestrial and aquatic species diversity, highlighting the added-value of soil bioengineering techniques to restore riparian biodiversity. This may confirm that stabilization structures made of willow fascines are better suited than stabilization structures made of artificial substrata to support riparian species. Also, beyond the positive effect of soil bioengineering techniques for riparian biodiversity, we found that climatic, hydrological and land cover variables strongly influenced diversity patterns. Thus, multi-taxonomic diversity decreased along larger rivers and in landscapes dominated by urban areas. This may indicate that the full added value of soil bioengineering techniques for biodiversity will only become apparent if more attention is paid to mitigating the negative impact of human activities in the vicinity of riparian zones and if larger scale environmental parameters are taken into account as early as possible in restoration project. Therefore, we strongly recommend that riverbank restoration projects, based on the active introduction of native pioneer tree species, should be planned at the catchment scale.

The riparian zone is a unique landscape component that represents an ecological transition between aquatic and terrestrial ecosystems. The restoration of riparian zones has become an ecological focus in the realms of both urban development planning and watershed management. This paper applies the concept of landsenses ecology, ecological restoration principles and a range of eco-revetment models in riparian zone restoration for Xianghe Segment of China’s Grand Canal (XSCGC). Based on field trip investigation, the restoration considerations involve the current status quo of the segment’s riparian zone. In addition to the analysis of key flood control areas, the restoration considers the main functions of various landscape components. The riparian zone is divided into five typical sections: the wetland ecological conservation section in the upper reaches, the wetland ecological conservation section in the lower reaches, the riverside leisure and entertainment section in the middle reaches, the resto...

On upstream of Hunhe River, the riparian zone and water quality has been impacted by increasing anthropogenic activities. Nitrogen and phosphorus run-off the river, has led to eutrophication. In this study, total nitrogen (TN) and total phosphorus (TP) concentrations were measured from different tissues (roots, stems and leaves) of twelve plants from the upstream riparian zone of the Hunhe River. The TN concentration ranged between 6.45 and 39.94 mg/g, while the TP range was 2.77–9.20 mg/g. A positive correlation of r 2 ¼ 0.5157, p < 0.05 was recorded between N/P ratios and TN. This showedthat plantsgrowth waslimitedbyNaccordingtothe“law ofthe minimum”.The concentrations of TN and TP in leaves were significantly higher than that in roots and stems. There were significant differences among life forms (tree, shrub, and herb) with respect to TP and N/P ratios. The data provided a theoretical guidance to plant species screening for the riparian zone restoration in purpose of the water quality improvement in the Hunhe River.

Monitoring is a fundamental aspect of restoration, as it determines when the restoration objectives have been met. As restoration objectives are not universal, monitoring needs to be included in the development and design of each restoration project. We assessed the effectiveness and efficiency of a forest stand dynamic monitoring plan, developed for use with riparian restoration occurring on Lyell Island, Haida Gwaii, British Columbia. The restoration objective is to accelerate the development of late-successional forests for the benefit of riparian wildlife species and recruitment of in-stream large woody debris, which specifically provides essential habitat for a variety of fish species. In this study large woody debris (LWD) is referred to as downed wood greater than 7.5 cm in diameter. Prior to the start of riparian restoration, two watersheds were quantified for their stand structure and composition using the forest stand dynamic monitoring plan. An error analysis of these data was used to assess the sampling efficiency of the monitoring plan. The design of the monitoring plan was found to be efficient at monitoring the riparian forest stand dynamics (with seven or eight plots per site sufficient to evaluate stand basal area and stem density to within 10%), but not woody debris volumes (for which deviations >10% were found even with 14 plots per site). Incorporation of additional line transects or adoption of more efficient sampling methods for woody debris (such as diameter or length relascope methods) is suggested as a means of enhancing large woody debris sampling efficiency.

Field studies were conducted on black willow (Salix nigra) cuttings planted for riparian zone restoration along Harland Creek, Twentymile Creek, and Little Topashaw Creek in Mississippi, USA. Planted cuttings were 2.5 to 3 m long and had base diameters of 2.5 to 7.5 cm. Streams were unstable, deeply incised sand bed channels with eroding banks 1 to 6 m high. Soil texture, redox potential (Eh), depth to water table, and willow survival were monitored for two to three years after planting. While many factors influence willow cuttings at restoration sites, soil texture and moisture are key to plant success. In these studies, plant survival and growth were best for cuttings planted in soils with less than 40 percent silt-clay content and a water table 0.5 m to 1.0 m below the soil surface during the growing season. These conditions produced soil Eh greater than approximately 200 mV and were most often observed 1 to 2 m higher than the bank toe. These findings suggest criteria useful for preplanting site evaluations. Additional evidence suggests that preplanting soaking enhances per- formance of black willow cuttings. Additional factors (channel erosion, herbivory by beaver, and competition from exotics) may control per- formance over periods longer than two to three years. (KEY TERMS: riverbank; restoration; incised channel; willow post; streambank erosion; riparian zones.)

Microbial biomass, nitrifiers and denitrifiers in surface soil (0–10 cm) were quantified in a riparian zone restoration project at Coweeta, North Carolina, USA. Four treatments are included in this study: (1) a degraded (+N) riparian zone with continued compaction, vegetation removal, and nutrient addition (mow, roll, and nutrient addition); (2) a degraded ( −N) riparian zone with continued compaction and vegetation removal, but without nutrient addition (mow and roll only); (3) a restored riparian area (no grazing, cessation of manure and N fertilizer application and re-vegetation with natural regrowth for 2 years); and (4) reference riparian zone (no riparian zone degradation has occurred within the last 10 years). Mean microbial biomass C increased from winter (316 mg kg −1 ) to summer (593 mg kg −1 ), and decreased from summer to fall (265 mg kg −1 ). There were no significant changes in microbial biomass C with the cessation of manure and chemical fertilizer application in the degraded − N plot and with re-vegetation in the restored plot as compared to the degraded + N plot. Microbial biomass C level in the restored plot was comparable to that in the reference plot for most seasons. Restored plots had significant greater populations of denitrifiers than reference plots in the spring. Nitrifier numbers were lower in the degraded − N and restored plots than the degraded + N. Ammonium oxidizers in summer were more abundant (25,000 g −1 soil) in the degraded + N plot compared to (1000 g −1 soil) in the degraded − N and restored plots, and NO2 − oxidizers in the same period were more abundant (130,000 g −1 soil) in the degraded + N plot than that in the degraded − N and restored plots about (40,000 g −1 soil). The soil NO3 − concentrations were considerably lower in the degraded − N and restored plots than the degraded + N plot. Our results imply either cessation of manure and N fertilizer application or cessation of manure and N fertilizer and re-vegetation could contribute to restoration of degraded riparian zone through reducing numbers of nitrifiers. © 2003 Elsevier B.V. All rights reserved.

Achievement of management goals for Lake Champlain (Vermont/New York, USA and Quebec, Canada) will require significant reductions of phosphorus (P) loads from agriculture, the dominant diffuse source in the basin. Cost-effective P reduction strategies must be based on reliable treatment techniques beyond basic erosion control and animal waste storage practices. The Lake Champlain Basin Agricultural Watersheds National Monitoring Program (NMP) Project evaluates the effectiveness of low-cost livestock exclusion, streambank protection, and riparian restoration practices in reducing concentrations and loads of diffuse-source pollutants from grazing land at the watershed level. Treatment and control watersheds in northwestern Vermont have been monitored since 1994 according to a paired-watershed design. Monitoring includes continuous stream discharge recording, flow-proportional sampling for total P and other pollutants, and documentation of land use and agricultural management activities. Strong statistical calibration between the control and treatment watersheds has been achieved. Landowner participation in the land treatment program was entirely voluntary and all treatments were 100% cost-shared by the project and cooperators. Installation of riparian fencing, alternative water supplies, protected stream crossings, and streambank bioengineering was completed in 1997 at a cost of less than US$40,000. The paired-watershed design was effective in controlling for the influence of extreme variations in precipitation and streamflow over six years of monitoring. Two years of post-treatment data have documented significant reductions in P concentrations and loads from both treated watersheds. Reductions of approximately 20% in mean total P concentration and approximately 20-50% in mean total P load have been observed, with greater reductions occurring in the watershed receiving more extensive treatment. The effectiveness of riparian zone restoration in P reduction tended to be lower during periods of very high runoff, especially outside the growing season.

Recently the US Army Corps of Engineers (the Corps) has increased the level of compensatory mitigation requirements for streams impacted by surface coal mining in the Appalachian coalfields. Through new permitting requirements (Nationwide Permit 21) the Corps is requiring that applicants submit a compensatory mitigation plan that will offset permanent and temporary losses of aquatic functions and values from fill of intermittent and ephemeral streams. These changes have led to concern by the regulated community over the cost of meeting mitigation requirements. In this study a cost analysis is conducted of projects that could be considered as compensatory mitigation The study estimates total costs for fourteen projects in the areas of channel and riparian zone restoration, abandoned mine land reclamation and acid mine drainage treatment. We conclude that costs are sensitive to project types and size, and a number of regulatory design issues including the regulatory criteria for acceptable mitigation.

Achievement of management goals for Lake Champlain will require significant reductions of phosphorus (P) loads from agriculture, the dominant nonpoint source (nps) in the Basin. Cost-effective nonpoint source reduction strategies must be based on reliable treatment techniques beyond the basic erosion control and animal waste storage practices promoted in the past. The Lake Champlain Basin Agricultural Watersheds National Monitoring Program (NMP) Project evaluated the effectiveness of low-cost livestock exclusion, streambank protection, and riparian restoration practices in reducing concentrations and loads of nps pollutants from grazing land at the watershed level. Treatment and control watersheds in the Missisquoi River Basin in northwestern Vermont were monitored from 1994 through 2000 in a paired-watershed design. Monitoring included stream discharge recording, flow-proportional sampling for nutrients and suspended solids, intensive grab sampling for indicator bacteria, and tracking of land use and agricultural management in the watersheds. Treatment (riparian fencing, alternative water supplies, protected stream crossings, and streambank bioengineering) was completed in 1997 at a cost of ~$40,000. Landowner participation in land treatment was entirely voluntary and all treatments were 100% cost-shared by the project and cooperators. Post-treatment data documented significant reductions in nutrient and suspended solids concentrations and loads (~20–50%) and bacteria counts (~40–60%) from both treated watersheds. Although water quality in one treated watershed was seriously compromised by mismanagement of one large farm in the final year, the project clearly demonstrated the potential for inexpensive riparian zone restoration to reduce nps pollution from grazing lands in Vermont.

Agricultural riparian zones are often vulnerable to weed invasion and degradation of the physical streambank character through the trampling of livestock. Riparian zone restoration seeks to improve habitat biodiversity, minimise streambank erosion and improve water quality. In order for this to be effective land managers need to broadly understand the connections between riparian systems and adjoining agricultural ecosystems and to understand the habitat requirements of wildlife species adapted to the evolving riparian landscape. Common wombats (Vombatus ursinus) are abundant in the riparian agricultural landscapes of south-eastern Australia, but there is concern about their persistence in other landscapes. To understand the importance of riparian characteristics for wombats, we examined five physical and five vegetative characteristics associated with abundance of wombat burrows in the riparian zone of an agricultural landscape in south-eastern New South Wales, using two independent datasets. The abundance of wombat burrows increased substantially with increasing shrub cover in both datasets. There was weaker but consistent support for an association between wombat burrows and stream order and vegetation width. There were more burrows per metre by high than low order streams and burrows were most abundant at an intermediate vegetation width. In one of the two datasets, burrow abundance declined as the proportion of native shrubs in the shrub layer increased. As wombats are generally limited to riparian buffers in agricultural landscapes, these results are important as a first step toward managing and restoring the riparian zone. Restoration strategies, for example, may need to consider retaining patches of shrubs, even if they are weeds, whereas native shrubs are established in interspersed patches along larger rivers, in order to maintain suitable wombat habitat.

The distribution patterns of dictyostelid cellular slime molds (CSM) in soils of 14 different study sites in the Kantishna Hills of Denali National Park and Preserve were investigated during the 1991 field season. Study sites included examples of all major natural vegetation types found in the region as well as a number of study plots representing different types of riparian zone restoration treatments being carried out as part of the National Park Service's Glen Creek Restoration Project. Six CSM species were isolated, but two of these-Dictyostelium mucoroides and D. sphaerocephalum-were overwhelming dominants. The total number of clones per gram of wet soil ranged from 0 to 1203, with an average value of 259 for all 14 study sites. The mean value recorded for the seven natural vegetation study sites (430) was considerably higher than the corresponding value (87) for the seven restoration study sites. Interestingly, D. mucoroides ranked as the dominant species (59-98% of all clones) for all six of the natural vegetation study sites from which CSM were isolated, whereas D. sphaerocephalum was dominant (50-100% of all clones) in the six restoration study plots with CSM present.

Geomorphic, hydraulic and hydrologic principles are applied in the design of a stable stream channel for a badly disturbed portion of Badger Creek, Colorado, and its associated riparian and meadow complexes. The objective is to shorten the period of time required for a channel in coarse alluvium to recover from an impacted morphologic state to a regime condition representative of current watershed conditions. Channel geometry measurements describe the stream channel and the normal bankfull stage in relatively stable reaches. Critical shear stress equations were used to design a stable channel in noncohesive materials with dimensions which approximate those of less disturbed reaches. Gabion controls, spaced at approximately 300 m intervals, are recommended to help reduce the chance of lateral migration of the newly constructed channel. Controls are designed to allow for some vertical adjustment of the channel bed following increased bank stability due to revegetation. The flood plain is designed to dissipate flood flow energy and discourage multiple flood channels. The channel has approximately a 90 percent chance of remaining stable the first two years following construction, the time estimated for increased stability to occur due to revegetation.